The wiretaps provided clinching evidence, leading to the prosecution and conviction of Rajaratnam and Gupta.

Last week, I wrote on how not to catch corporate and political crooks. Readers naturally asked, what is the right way?

Some analysts say India has only 1.3 policemen per 1,000 citizens against 2.5 in the US, 5.3 in Turkey and 5.5 in Russia. But China has only 1.2 per 1,000, yet convicts and executes hundreds of crooks every year. Much can be achieved even with our limited forces provided they have better training, better equipment, and (above all) better procedures.

In any crime, the police first register a preliminary enquiry (PE). If they find hanky-panky , they register a First Information Report (FIR). And if that unearths substantive evidence, they file a chargesheet. Every PE and FIR today is announced with much hoopla. Alas, those named in PEs and FIRs are tarnished in the public eye even if they have little or no connection with the crime. Worse, public naming in a PE gives actual crooks advance notice of investigations, enabling them to totally cover their tracks. No wonder raids rarely uncover anything. Only careless crooks get caught.

To see how ridiculous and ineffective our procedures are, consider how US investigators caught Raj Rajaratnam and Rajat Gupta in the biggest US insider trading case. Astonishingly, US investigations continued in secret for a full decade, lulling Rajaratnam into false security. No information leaked out to politicians, Wall Street, or the crooks.

The US Securities and Exchange Commission (SEC) supervises trading. For years it suspected Rajaratnam of insider trading, but routine hearings and examinations of his books failed to uncover firm evidence. Nevertheless a tireless SEC investigator, Sanjay Wadhwa, pursued the trail for years.

Then he got a break. One of Rajaratnam's informers, Romy Khan, was snapped by an office camera faxing documents to Rajaratnam. The SEC cracked down, and Khan confessed.

But Wadhwa judged that the confession was not enough. Linking the documents Khan faxed to Rajaratnam with killer trades proved difficult. Rajaratnam traded $12 billion of stocks per day, and had intimate market knowledge plus huge research inputs. Provided he was not blatant, he could claim that his successful trades were based on legitimate analysis, not insider information.

Wadhwa's investigations continued, and he eventually joined hands with New York District Attorney Preet Bharara. They got court permission to tap Rajaratnam's phones. The tapping continued for almost two years, and revealed an unexpected crook: Rajat Gupta. A board member of Goldman Sachs, he would phone Rajaratnam within minutes of a board meeting, facilitating immediate trades yielding millions in profit. The wiretaps provided clinching evidence, leading to the prosecution and conviction of Rajaratnam and Gupta.

What are the main lessons? First, we need independent investigative agencies that pursue cases over long periods, free from frequent transfers and political interference. Second, we need complete secrecy in investigations. Third, we need legal but intelligent use of wiretaps for clinching evidence.

Alas, instead of secrecy or perseverance, India's police and politicians give huge publicity to shallow PEs and FIRs without clinching evidence. This alerts all crooks, while tainting innocents. This must stop: PEs and FIRs must be kept secret.

Second, home ministers have iron control over the police, so neither independence nor secrecy of investigations is possible. We need to delink criminal investigations from the home ministry. We could consider adopting the US system of district attorneys, independent of state governments, who attain fame through successful prosecutions. This makes them candidates for higher political office, a huge incentive for performance. By contrast, Indian prosecutors are hacks controlled by home ministers, with no incentive to excel.

Third, investigative agencies must get wiretap permission from the courts in secrecy, without alerting politicians and their chums.

Instead, PEs and FIRs are revealed with fanfare to the media. This tips off actual crooks. India has no tradition of police secrecy, or police independence, or long police tenures enabling officers to chase cases for a decade. State home ministers decide what cases to pursue or drop, leak information to buddies, protect friends and launch vendettas against foes.

Thus cronyism is embedded not just in crooked deals but in police procedures and practice. Narendra Modi and Arvind Kejriwal show no awareness of this, but it explains why so few crooks are caught today. A total overhaul of police procedures is essential, buttressed by judicial reforms to ensure speedy court procedures. If Modi and Kejriwal are serious about curbing corruption, they must launch major police and judicial reforms. Otherwise crooks and cronies will keep flourishing. The task is enormous, but a start must be made.